Development drilling for field depletion planning involves optimization of a wide variety of parameters including drill center location(s), drill center slot design and assignment, reservoir target location(s), well trajectory and shallow hazard avoidance all while minimizing drilling cost and risk. These wide varieties of factors are often in conflict when finalizing well paths and drill center locations. Current field planning and drill center design practices are often sequential and inefficient for these various reasons.
For example:                1. Geoscientists select potential target locations based on the geologic interpretation and understanding of the distribution of subsurface reservoir properties.        2. Multiple well trajectories are designed to penetrate favorable reservoir properties and given to the drilling engineer for more detailed well design and analysis.        3. Drill center locations are selected or modified based on the analysis of these well designs.        4. Because of the complexity of the well paths and reservoir requirements, tradeoffs to the target location(s), number of targets, basic trajectory parameters and drill center locations need to be made.        5. The final drill center locations and well trajectories may take multiple trial and error iterations and still may not yield the optimal solution.        
The length of time taken to iterate between drill center and target locations can limit the number of scenarios examined and lead to sub-optimal results.
Drilling operations require complex steps and processes in order to derive maximum return with minimum cost. At the same time, the well site selection also needs to consider the environmental impact. Drill center selection and well plan optimization processes usually derive an ‘optimal’ solution that is based on certain rigid constraints. The end result of the process provides limited choices and little insight into the solution space to the user. In order to obtain a different ‘optimal’ solution, the users would experiment by modifying certain parameters in the optimization process.